orologio en CB01 OFFICIAL. U.D.O. live at Wacken with special guests. U.D.O. is a German power metal band founded by lead singer Udo Dirkschneider in 1987. Wacken Open Air (W:O:A) is a summer open air heavy metal music festival. It takes place annually in the small village of Wacken in Schleswig-Holstein,